Optimal cervical-ripening method for labor induction in Japan after the era of controlled-release dinoprostone vaginal insert.

OBJECTIVE: To investigate the predictive value of obstetric findings when using dinoprostone (prostaglandin E2 [PGE2]) vaginal inserts for cervical ripening, and to assess the optimal cervical-ripening method between PGE2 vaginal insert and/or cervical dilators. METHODS: This prospective observational study enrolled pregnant women who underwent cervical ripening for labor induction in 37-41 week' gestation in 2020. In evaluation 1, optimal obstetric findings predictive of rapid cervical ripening using PGE2 were assessed. In evaluation 2, the duration from PGE2 administration to labor onset and perinatal outcomes were compared between cases in which only PGE2 was used and cases that were treated with PGE2 after mechanical cervical dilators (Dilapan®) for extremely immature cervical ripening (uterine cervical os <2 cm). RESULTS: In evaluation 1, uterine dilatation before the use of a PGE2 vaginal insert was mostly correlated with the time from PGE2 administration to labor onset (r = -0.428, p < 0.001). When the uterine cervical os dilatation was ≥2 cm, a shorter time-to-labor onset was found. In addition, os dilatation, effacement, and station at the time of PGE2 vaginal insert removal also significantly progressed. In evaluation 2, the median duration from PGE2 administration to labor onset was 1740 min in cases where only PGE2 was used, and 610 min in those where PGE2 was used after mechanical cervical dilators (p = 0.011). CONCLUSION: PGE2 vaginal inserts are relatively effective when the uterine cervical os is ≥2 cm in diameter. However, in cases of extremely immature cervical-ripening, it was feasible to use PGE2 vaginal inserts before mechanical cervical dilatation.

Effect of epidural analgesia on cervical ripening using dinoprostone vaginal inserts.

OBJECTIVE: To clarify whether the duration from cervical ripening induction to labor onset is prolonged when epidural analgesia is administered following application of dinoprostone vaginal inserts vs. cervical ripening balloon. METHODS: This retrospective study included mothers with singleton deliveries at a single center between 2020-2021. Nulliparous women who underwent labor induction and requested epidural analgesia during labor after 37 weeks of gestation were included. The duration from cervical ripening induction to labor onset was compared between women using a dinoprostone vaginal insert and those using a cervical ripening balloon and between women who received epidural analgesia before and after labor onset. RESULTS: In the dinoprostone vaginal insert group, the duration was significantly shorter in the subgroup that received epidural analgesia after labor onset (estimated median, 545 [95% confidence interval: 229-861 min]) than the subgroup that received it before labor onset (estimated median, 1,570 [95% confidence interval: 1,226-1,914] min, p = 0.004). However, in the cervical ripening balloon group, the difference between subgroups was not significant. The length of labor among the groups was also not significantly different. CONCLUSION: Epidural analgesia as labor relaxant adversely affected the progression of uterine cervical ripening when dinoprostone vaginal inserts were used, whereas it did not affect cervical ripening when a mechanical cervical dilatation balloon was used. The present results are significant for choosing the appropriate ripening method.

COVID-19 mRNA vaccination status and concerns among pregnant women in Japan: a multicenter questionnaire survey.

BACKGROUND: mRNA vaccination is an effective, safe, and widespread strategy for protecting pregnant women against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, information on factors such as perinatal outcomes, safety, and coverage of mRNA vaccinations among pregnant women is limited in Japan. Therefore, this study aimed to investigate the perinatal outcomes, coverage, adverse effects, and short-term safety of mRNA vaccination as well as vaccine hesitancy among pregnant women. METHODS: We conducted a multicenter online survey of postpartum women who delivered their offspring at 15 institutions around Tokyo from October 2021 to March 2022. Postpartum women were divided into vaccinated and unvaccinated groups. Perinatal outcomes, COVID-19 prevalence, and disease severity were compared between the two groups. Adverse reactions in the vaccinated group and the reasons for being unvaccinated were also investigated retrospectively. RESULTS: A total of 1,051 eligible postpartum women were included. Of these, 834 (79.4%) had received an mRNA vaccine, while 217 (20.6%) had not, mainly due to concerns about the effect of vaccination on the fetus. Vaccination did not increase the incidence of adverse perinatal outcomes, including fetal morphological abnormalities. The vaccinated group demonstrated low COVID-19 morbidity and severity. In the vaccinated group, the preterm birth rate, cesarean section rate, and COVID-19 incidence were 7.2%, 33.2%, and 3.3%, respectively, compared with the 13.7%, 42.2%, and 7.8% in the unvaccinated group, respectively. Almost no serious adverse reactions were associated with vaccination. CONCLUSIONS: mRNA vaccines did not demonstrate any adverse effects pertaining to short-term perinatal outcomes and might have prevented SARS-CoV-2 infection or reduced COVID-19 severity. Concerns regarding the safety of the vaccine in relation to the fetus and the mother were the main reasons that prevented pregnant women from being vaccinated. To resolve concerns, it is necessary to conduct further research to confirm not only the short-term safety but also the long-term safety of mRNA vaccines.

Individualized management of vasa previa and neonatal outcomes.

OBJECTIVE: To describe our individualized management protocol for women with an antenatal diagnosis of vasa previa (VP) and to report maternal and neonatal outcomes in patients managed according to our protocol. METHODS: A retrospective study of prospectively collected data of antenatally diagnosed VP managed at our hospital between 2014 and 2021. Obstetric and neonatal outcomes were reviewed and analyzed. RESULTS: Fourteen cases of antenatally diagnosed VP in 5150 total deliveries were analyzed (0.3%) Five cases (36%) of VP were diagnosed during the routine fetal morphological ultrasound screening, and nine cases (64%) were referred to our hospital due to perinatal complications. There were nine cases that required hospitalization (due to fetal growth restriction [FGR] [1], preterm labor [3], patients' request [5]). The other five were asymptomatic. Eight patients were delivered by scheduled cesarean section at around 36 weeks and only three neonates were admitted to NICU with transient tachypnea of newborn. However, six patients required CS before the scheduled dates because of other complications (preterm labor [3], abnormal cardiotocogram patterns [1], FGR [1] and twin pregnancy [1]). Four neonates born by CS before their scheduled dates were admitted to NICU. No cases required prolonged hospitalization and there were no serious neonatal complications. CONCLUSION: Individualized management may lead to favorable outcomes with VP. Outpatient management may be considered in patients without risk factors. However, maternal hospitalization and earlier scheduled CS should be considered in symptomatic patients or those at risk for preterm delivery.

Accuracy of predicting neonatal distress using a five-level classification of fetal heart rate monitoring.

AIM: To assess the accuracy of neonatal distress prediction using the five-level classification of fetal heart rate (FHR) and management protocol of the Japan Society of Obstetrics and Gynecology (JSOG). METHODS: A case-control study was conducted. Vertex singleton pregnant women who delivered after 37 weeks' gestation from 2013 to 2015 were enrolled. The participants were categorized into two groups; controls were levels 1-3 (n = 1184), whereas cases were levels 4-5 (n = 117) group. Neonatal distress was defined as Apgar score < 8 points at 5 min or umbilical cord artery pH < 7.1. RESULTS: There were 117 cases (9.0%). The frequency of the neonatal distress was observed in 1.3% controls and 6.8% cases (P < 0.01). Diagnostic accuracy of neonatal distress for cases showed a 6.8% positive-predictive value, 34.8% sensitivity, 91.5% specificity and 98.7% negative-predictive value. Among various obstetrical conditions, high sensitivity (100%) for prediction of neonatal distress was observed in women with chromosome abnormalities, placental abruption, umbilical cord abnormalities and excessive labor pain. Conversely, relatively low specificity (<50%) was observed in cases with oligohydramnios and excessive labor pain. CONCLUSION: The five-level classification scheme was efficient for neonatal distress prediction. However, depending on the obstetric condition, the FHR findings and neonatal condition might be independent.

Ultrasound screening and management of vasa previa in Japan.

AIM: This study aimed to clarify ultrasound screening and management for vasa previa (VP) in perinatal centers and primary facilities in Japan. METHODS: A questionnaire survey about antepartum ultrasound screening and management for VP was delivered in 2018. Questions were sent by email or post to perinatal centers and randomly selected primary hospitals or clinics throughout Japan. RESULTS: Seventy-seven perinatal centers and 300 primary facilities answered. VP was screened in 85.7% of perinatal centers and 81.3% of primary facilities. The reported incidence of VP was 0.05% (86/158 323) and 0.05% (28/54 791) in perinatal centers and primary facilities, respectively. When patients were diagnosed with VP, 88.7% of primary facilities referred the patient to a tertiary hospital. Routine hospitalization (100%) and steroid administration (46%) were frequently performed in perinatal centers. The median gestational age at planned cesarean section was significantly earlier in perinatal centers (34 weeks) than in primary facilities (37 weeks). Of the 31 reported cases of VP, 30 were reported as intact survival, but 1 case required an emergency cesarean section at 38 weeks of gestation without an antenatal diagnosis, resulting in neonatal death. CONCLUSION: More than 80% of obstetric facilities both perinatal centers and clinics in Japan perform ultrasound screening with for VP with similar detection rate. However, to further improve perinatal outcomes related to VP, pathophysiology and diagnosis of VP should be more widely recognized by obstetric caregivers throughout Japan.

Declaration of emergency state due to COVID-19 spread in Japan reduced maternal transports without reduction in preterm delivery.

INTRODUCTION: To clarify whether the declaration of an emergency state due to the spread of COVID-19 in Japan affected the number of maternal transports and premature births. METHODS: A questionnaire-based descriptive study was conducted in perinatal centers throughout Japan in 2020. The incidence of maternal transport and preterm delivery rates every month after the COVID-19 spread in 2020 were compared with those in 2019. RESULTS: Participants were recruited from 52 perinatal centres. The maternal transport rate (maternal transports per number of deliveries) was 10.6% in April and 11.0% in June 2020, compared with 12.5% in 2019 (P < 0.05). The maternal transport rate due to preterm labor was 4.8% in April 2020 and 5.8% in 2019 (P < 0.05). The maternal transport rate during the declaration of emergency state decreased by 21% in April 2020 in non-emergency-declared prefectures, and decreased by 17% in May 2020 in emergency-declared prefectures. However, there was no significant difference in the preterm delivery rate between 2020 and 2019, regardless of the prefecture and gestational period. CONCLUSION: Declaration of the emergency status due to COVID-19 spread in Japan reduced maternal transport due to preterm labor, but did not reduce preterm delivery itself.

Ultrasound Doppler Findings in Fetal Vascular Malperfusion Due to Umbilical Cord Abnormalities: A Pilot Case Predictive for Cerebral Palsy.

Fetal Vascular Malperfusion (FVM), a pathologic condition in the feto-placental circulation, is a chronic vaso-occlusive disorder in the umbilical venous blood flow. Microthrombi are caused by the umbilical cord's blood flow deficiency in a congested umbilical vein, which also causes microvascular damage to fetal organs, especially the brain, resulting in cerebral palsy. Thrombo-occlusive events also adversely affect the upstream chorionic or stem vessels in the placenta, resulting in fetal growth restriction and fetal hypoxia. An umbilical cord structural anomaly or multiple entanglements may involve FVM. In the present report, we demonstrate a case of FVM caused by multiple umbilical cord abnormalities obtained from antenatal ultrasound Doppler findings, and we also discuss FVM, which is chronically associated with CP, comparing the ultrasonographic findings to the pathologic findings.

Accuracy of Prenatal Ultrasound in Evaluating Placental Pathology Using Superb Microvascular Imaging: A Prospective Observation Study.

Superb microvascular imaging (SMI) is a new Doppler method that enables the visualization of low-velocity blood flow. The aim of the study described here was to clarify whether SMI can detect prenatal pathological findings in pathologic placentas. In this prospective diagnostic observational study, pregnant women who were admitted to our center for perinatal management were enrolled. Ultrasound examinations to identify placental pathologies using SMI were performed before delivery. After delivery, the placental tissue was clipped for microscopic examination at locations determined under ultrasound guidance. The accuracy of prenatal ultrasound detection of placental pathologies was compared between women who were admitted because of fetal growth restriction (FGR), pre-eclampsia and other indications. The highest accuracy was observed with placental infarction in FGR (positive predictive value = 100%, sensitivity = 89%, area under the curve = 0.945). As a result, it became clear that SMI can accurately detect placental pathologic findings, such as placental infarction and avascular villi. This modality may improve perinatal management in cases of placental dysfunction.

Ultrasonographic findings of placental abruption observed on superb microvascular imaging.

OBJECTIVE: To demonstrate ultrasound pathological findings of placental abruption (PA) detected using a new Doppler method: superb microvascular imaging (SMI). CASE REPORT: The patient was a pregnant woman with dark brown vaginal discharge at 32 + 4 weeks of gestation. Conventional ultrasound revealed an exophytic heterogeneous area measuring 3 cm, between the placenta and myometrium. SMI showed no minor blood flow inside the area. A diagnosis of marginal sub-chorionic hematoma was made. On the seventh day of hospitalization, SMI showed pulsation of blood flow in the inter-villous space and fetal blood flow in the villous trees. Due to an increase in the frequency of uterine contractions, an emergency cesarean section was performed. Histopathological examination showed hematomas beneath the decidual tissue, and the decidual layer was undamaged. The inter-villous space was preserved. CONCLUSION: SMI can contribute to a more accurate PA diagnosis that may lead to timely administration of obstetric intervention.

Histological Assessment of the Placenta Accreta Spectrum Diagnosed with a 33-MHz Linear Probe during Cesarean Section.

As placenta accreta spectrum (PAS) pathologies affect only the extremely thin tissues between the placenta and the uterine myometrium, superficial endometrial damage such as that caused by placenta creta and increta can be diagnosed only through histopathology. We performed direct uterine ultrasound of PAS using an ultrahigh frequency (33 MHz; i33LX9 Aplio i800) linear transducer. Here, we describe two cases with ultrasound images of placentas with PAS and a case without PAS to compare histological findings. In cases of PAS at the previous Cesarean scar, ultrasonography clearly revealed a thin uterine myometrium with some island-shaped sites where placental tissue was focally anchored to the uterine myometrium near the scar. Speckle blood flow pattern was absent at these sites during scanning with B-mode, but was detectable elsewhere. Histopathology samples from the same site revealed that villous tissue was directly attached to the uterine myometrium with a large area of infarction. In another case of diffuse PAS, speckle blood flow pattern was generally absent, and histopathology revealed deep fibrinoid deposits. We believe that histological evaluation following ultrasound use will improve the accuracy of ultrasound diagnosis and perinatal management of PAS in clinical practice.

Novel ultrasound assessment of placental pathological function using superb microvascular imaging.

Ultrasound Doppler method of Superb Microvascular Imaging (SMI) can significantly visualize low-velocity blood flow using a unique algorithm. We scanned placenta antenatally using SMI and compared those findings with histological findings after delivery in cases with placental abnormalities. In normal, SMI expresses stem villous vessels connecting to the tertiary villous vessels which are sharply diminished, and expresses intervillous blood flow as "scatter." Placental infarction was expressed as an anechoic area in SMI. Avascular villi was expressed as absent villous blood trees in a background scatter flow in SMI. In this report, we demonstrated typical SMI findings of the pathologic placenta as a pilot study.

Sono-embryological assessments of a true knot that developed into a hypercoiled cord and circumvallate placenta.

Longitudinal investigations using ultrasound during pregnancy can be used to clarify the mechanisms and pathophysiology of abnormal fetal and placental development. In this report, we presented a case of a true knot that appeared to develop into a hypercoiled cord and circumvallate placenta, which we found through longitudinal ultrasound investigations during pregnancy. In the present case, ultrasonography proved that the true knot had existed at least 16 weeks of gestation. The true knot was presumed to develop into a hypercoiled cord based on the hypothesis of differential umbilical vascular growth rates.